Computer systems typically display a digital image stored therein on their cathode ray tube (CRT) or liquid crystal display monitors. The image is typically displayed so as to fill most, if not all, of the monitor surface. The computer user can then view the image.
Unfortunately, computer monitors are typically quite small such that only one or two people can view the image displayed thereon. Therefore, it is known to project a digital image stored in a computer onto a large display. However, such a projection is of low resolution since each pixel on the computer monitor is translated into a single, large pixel of the large display.
Alternatively and as shown in FIG. 1 to which reference is now made, the digital image 10 can be displayed onto a "video wall" 12 formed of many monitors 14 next to each other in a matrix. Each monitor 14 of the video wall 12 receives only a section 16 of the image to be displayed. Thus, section 16a is projected onto monitor 14a, section 16b is projected onto monitor 14b, etc. The resultant large image is of approximately the same resolution as the stored image 10. However, since the large image is displayed on separate monitors 14, there are seams 18 in the large image viewed by the viewer 19.
NTT Corporation of Japan reported, in the Japan Hi-Tech Report, a large format, liquid crystal projector which utilizes four LCD basic projection units, each projecting one-quarter of the image to be displayed. The large format projector includes liquid prisms for superimposing the sub-images and controlling their exact locations on the display surface. Such a system has no seams 18 but has mechanical problems due to the need to align four basic projection units. The projection units can become mis-aligned over time due to thermal expansion or contraction of optical elements or due to wear and tear of mechanical alignment elements. This misalignment of the projection units will cause the large format image to become skewed.
Black Box Vision has produced a hoarding display system which has a series of LCD "bricks" which can be pieced together into screens. As described with respect to FIG. 1, there are seams between the bricks.